题文

阅读理解。

When the traffic lights turn red, we will stop driving a car or crossing a street. Why is red used for traffic lights instead of other colors?      As we know, scattering (散射) happens when light goes through the air. For the same media (媒质), if the wavelength is long, the scattering will be short. If the wavelength is short, then the scattering will be long.      Of all lights we can see red has the longest wavelength, so the scattering is the weakest. That means the red light travels far. In fact, it travels farther on rainy days.      Using the red light can help drivers in farther areas sec the lights. It helps drivers stow down or stop in lime. If drivers don't see the red light until they are close, they may not be able to stop the car in time. An accident may happen Red can also excite people. We can act more quickly when we see the color red. In a word, red lights help drivers stop in time and help prevent accidents.

1. When the traffic lights turn ______, we will stop driving a car.

A. red B. green C. yellow

2. According to the passage, the scattering of the red light is the _______.

A. longest B. weakest C. farthest

3. The underlined word "wavelength" means________ in Chinese.

A. 波浪 B. 光波 C. 波长

4. What can the red light help drivers do?

A. It can help drivers in farther areas see the lights. B. It can help drivers slow down or stop in time. C. A and B

5. Which of the following is the best title?

A. Why do accidents happen B. How does the red light travel C. Why do we use red traffic lights

题型：阅读理解  难度：中档

答案

1-5      ABCCC

据专家权威分析，试题“阅读理解。 When the traffic lights turn red, we will stop dr..”主要考查你对  科教类阅读  等考点的理解。关于这些考点的“档案”如下：

科教类阅读

考点名称：科教类阅读

• 科普类的阅读：
  科普类的阅读理解包含介绍科学知识、社会知识的短文。阅读这类短文时，要以事实为中心进行思考，抓住事物的特征、用途、相互关系等。
  如果是介绍社会现象的文章，要掌握所谈现象的内涵。

• 答题技巧：
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     关键词做上记号，尤其是各段中心句，为答题提供更快捷更多的信息源。
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